1. Field of the Invention
This invention relates to an apparatus for three-dimensional viewing of MRI tomograms which permits non-invasive viewing of tissues inside a living body three-dimensionally and in real time.
2. Prior Art Statement
The technique of magnetic resonance imaging (MRI) is making major contributions to various fields of modern medicine. MRI allows tomograms of tissues at any cross section within a living body to be represented as images of light and dark contrast. Moreover, this contrast is based on variations in the types and proportions of the constituent atoms in the chemical substances which make up these tissues, so images can be obtained which emphasize only particular portions of the tissues which have the same chemical composition, e.g. blood vessels only, bones only or abnormal tissues occurring on internal organs.
The MRI scanners used for such MRI are able to obtain three-dimensional information regarding tissues within the body, but the images actually displayed as output are limited to tomograms of one selected cross section among many mutually-parallel cross sections which are cut thinly to a selected width perpendicular to one selected direction. Since these are two-dimensional images, when attempting to view inside tissues within the body with this apparatus, one must select these cross sections and view the resulting tomograms one at a time on a display. In order to view several tomograms simultaneously, the images must be developed on film or the like, thus taking time which prevents real-time diagnosis and treatment, possibly delaying treatment. Furthermore, even when developed, accurate visual reconstruction of the original tissue in three dimensions from the individual tomograms is difficult, requiring a large amount of experience.
The present invention came about in light of the above, and its object is to provide an apparatus for three-dimensional viewing of MRI tomograms which is able to reconstruct a plurality of tomograms at mutually-parallel cross sections as a group of virtual images lined up in one direction to give the same perception of depth as if they were in their original positions within the bodily tissue, which can be viewed by the observer three-dimensionally in real time; thereby eliminating the labor and time required for film development, and also allowing the point of view to be moved to allow a desired portion to be seen, as in the case when a shadow in one tomograph in the foreground obscures a portion of a tomograph behind it which one wishes to view.